iPhone users warned over four characters of doom you should never type

iPhone users have this week been left baffled after discovering that a bug which has the ability to crash your device can be caused by typing just four characters.

Back in June, iPhone holders were advised not to download the latest beta iOS 18 update from the tech firm itself, amid fears it could contain bugs.

Weeks later, iPhone owners who are guilty of leaving their phone to charge overnight while they sleep were issued an extremely harrowing warning by health experts.

Several users have been left baffled by the bug. (Oscar Wong/Getty)

And just last week, some users were horrified to discover the existence of a 'vampire setting', which had been draining their mobile phones of precious battery.

However this week, a batch of Apple customers have discovered an apparent bug on their device.

The bizarre discovery has somehow been found by users who took a chance at typing a very specific four characters into two even more particular search bars.

The four doomed characters are "":: and users can't believe why. (Tyla)

What are the 'doomed' letters?

Well, it's two double-quotation marks, followed by two colons, typed consecutively with no spaces between.

Basically, this - ""::

Where shouldn't you type them?

As we say, these letters won't pose any issue to your device if you type them into a text to someone, or you search the characters on Safari.

There are two places within your iPhone, however, that you absolutely want to avoid typing them into.

The first being that search bar that appears when you open up your Settings, and the second being the app library search's bar, which you can access by swiping all the way to the right of your screen.

What happens if you do it?

Whilst your device might not burst into flames, or never turn back on again, doing this can actually briefly crash the system.

The bug turns users' screens black. (FreshSplash/Getty)

Those of you brave enough to try it out will notice your iPhone screen turn black, before a tiny loading wheel appears, and you home screen pops back up.

And though this 'bug' mightn't sound too dramatic, being that iPhones now commonly hold vital information - bank details, home information, vital emails - some users are worried that this glitch might have more serious consequences.

Thankfully, however, according to tech experts at TechCrunch - who spoke to The Sun this week - there is no indication that this does pose a threat to security, and isn't something we should worry too much about.

Tyla contacted Apple for comment.